TABLE OF CONTENTS

03-N2OPd

DESCRIPTION

This file contains the input data for the pw.x and neb.x calculations of N2O dissociation on Pd(110)-c(2x2)-2L, which are used by the 36a-neb-N2OPd, 36b-flo-N2OPd, and 36c-sbco-N2OPd examples, files: neb-N2OPd.pwtk - flo-N2OPd.pwtk - sbco-N2OPd.pwtk

EXAMPLE SOURCE FILE

N2OPd.pwtk

SOURCE

# BEWARE: the used parameters & thresholds are of low quality for the sake of speed

PATH {
    nstep_path = 400
    opt_scheme = 'broyden'
    num_of_images = 7
    use_freezing = .true.
}

CONTROL {
    calculation   = "relax"
    nstep = 100
}

SYSTEM {
    ibrav       = 0
    celldm(1)   = 9.193
    
    nat         = 9
    ntyp        = 3

    ! low cutoffs to speed-up
    ecutwfc     = 20.0
    ecutrho     = 120.0
    
    occupations = "smearing"
    smearing    = "methfessel-paxton"
    degauss     = 0.03
}

ELECTRONS {
    conv_thr    =  1.0e-9
    mixing_beta =  0.3
}

IONS {
    upscale =  1.0
}

ATOMIC_SPECIES {
    N     1.0  N.pbe-rrkjus.UPF
    O     1.0  O.pbe-rrkjus.UPF
    Pd    1.0  Pd.pbe-nd-rrkjus.UPF
}

# N.B. math expressions can be used in cards but they should contain no spaces

CELL_PARAMETERS { alat } {
    +sqrt(3)/3   sqrt(2)/sqrt(3)   0.0
    -sqrt(3)/3   sqrt(2)/sqrt(3)   0.0
     0.0000000   0.0000000000000   3.1
}

K_POINTS { automatic } {
    3 3 1   1 1 1
}

# this is the first image (it will be used in pw.x and neb.x
# calculations); we store it in a variable to easily reuse it

set first_image {
    O      0.394939    0.394939    0.327987
    N      0.240927    0.240927    0.329417
    N      0.102798    0.102798    0.294638
    Pd     0.500000    0.500000    0.174915
    Pd     0.000000    0.000000    0.176367
    Pd     0.000000    0.500000    0.084302
    Pd     0.500000    0.000000    0.084302
    Pd     0.500000    0.500000    0.000000   0 0 0
    Pd     0.000000    0.000000    0.000000   0 0 0
}

# for pw.x

ATOMIC_POSITIONS crystal $first_image


# for neb.x
#
# N.B:
#
# 1. in the neb.x input, there is the BEGIN_POSITIONS ... END_POSITIONS
#    supercard, but PWTK uses POSITIONS { ... } instead
#
# 2. double quotes are used instead of curly braces to utilize the value of $first_image

POSITIONS "
    FIRST_IMAGE
    ATOMIC_POSITIONS crystal
    $first_image

    LAST_IMAGE
    ATOMIC_POSITIONS crystal 
    O      0.521911    0.521911    0.293150
    N      0.141236    0.141236    0.376158
    N      0.092128    0.092128    0.306614
    Pd     0.500000    0.500000    0.171888
    Pd     0.000000    0.000000    0.175070
    Pd     0.000000    0.500000    0.083893
    Pd     0.500000    0.000000    0.083893
    Pd     0.500000    0.500000    0.000000
    Pd     0.000000    0.000000    0.000000
"